test: Remove obsolete tests. rs=buildbot

src/test/compile-fail/deprecated-mode-fn-arg.rs

@@ -1,9 +0,0 @@
-#[forbid(deprecated_mode)];
-
-fn foo(_f: fn(&i: int)) { //~ ERROR by-mutable-reference mode
-}
-
-type Bar = fn(&i: int); //~ ERROR by-mutable-reference mode
-
-fn main() {
-}

src/test/compile-fail/unnamed_argument_mode.rs

@@ -1,11 +0,0 @@
-//error-pattern: by-mutable-reference mode
-
-fn bad(&a: int) {
-}
-
-fn called(f: fn(&int)) {
-}
-
-fn main() {
-called(bad);
-}